\subsection{Smartphones/Tablets Used in Combination with a Main Screen}
Smartphones and tablets have made a lot of technology common household items, such as touchscreens, motion sensors and wireless communication. In a context where one screen is the main focus, few games have used smartphones and tablets as an input device for a game on the main screen.

\begin{itemize}
\item \textbf{Input/output}: Touchscreen, sound, vibration, motion sensors, camera, GPS, network capabilities. Typically, they lack physical buttons.
\item \textbf{Social}: Each player has their own device and therefore may put too much focus on their own screen instead of other players.
\item \textbf{Market penetration}: According to \citep{smartphone_stats}, more than 22\% of the world's population owns a smartphone, and more than 6\% owns a tablet.
\end{itemize}

\underline{Assessing The Applicability}

Despite the many technologies modern smartphones and tablets offer, there is one major drawback in regards to games: touchscreens have poor tactile feedback in comparison to traditional buttons. This means that traditional games work quite poorly on a touchscreen. An example of this is \textit{Space Bugz} by \citep{spaceBugz_paper}, where smartphones are used as controllers to move characters around on a big screen (see Figure \ref{fig:spaceBugz}). Although the idea of using a smartphone (a device many people own) to control a game on a big screen (say, in a cinema) is interesting, the fact that you cannot feel the buttons make the game hard to control. Oftentimes, you have to look down on the screen to see where your fingers are placed in relation to the virtual buttons. This might affect the social experience of playing a multiplayer game, since each player focuses too much on looking at his own screen. A different approach is to use motion-based controls, e.g.\ via the accelerometer, but this can lead to imprecise controls.

That being said, it is still worth having in mind how popular smartphones and tablets are. Thanks to app stores, it is easy and quick to download new games, and it typically does not require a lot of setup time to play them.

\begin{figure}[htbp]
\centering
\includegraphics[width=0.50\textwidth]{Pictures/Design/spacebugz}
\caption{\textit{Space Bugz} uses smartphones as input to control characters on the big screen \citep{spaceBugz_paper}.}
\label{fig:spaceBugz}
\end{figure}